Numerous different constructions of such switching units are known. For example, it has been proposed to construct the electrical components in a casing base with a threaded lug, the insertion opening being closed by a cover. The casing base can e.g. be formed by a reducing piece and the cover is screwed on. Such a unit can be screwed to a conventional cable connection box by internally threaded cable bushings, the connections of the unit being passed through an externally threaded lug.
The problem of the invention is to construct such an electronic switching unit in compact manner integrated with connecting devices for the connection of external connection lines or leads, so that it can be used independently of separate connection boxes.